Dibenzo(b,h)(1,5)diazecines



United States Patent 3,497,499 DIBENZO[b,h] [1,5]DIAZECINES William J. Houlihan, Mountain Lakes, and Robert E. Manning, Parsippany, N.J., assignors to Sandoz-Wander, Inc., a corporation of Delaware N0 Drawing. Filed Mar. 15, 1967, Ser. No. 623,238 Int. Cl. C07d 53/00, 51/48 US. Cl. 260-239 3 Claims ABSTRACT OF THE DISCLOSURE The compounds are of the class of dibenzo[b,h] [1,5] diazecines, e.g. 8,9-dimethoxy-13-methy1-5,6,l1,12,13,14- hexahydrodibenzo[b,h][l,5]diazecine, and pharmaceutically acceptable acid addition and quaternary ammonium salts thereof, useful as central nervous system stimulants and as hypotensives. The compounds may be obtained by condensing a 3,4-dihydroisoquinoline with an isatoic anhydride to form a 5,6,13,l3a-tetrahydro-8H-isoquino [1,2-b]quinazolin-S-one, which is then reduced, e.g. by heating with lithium aluminum hydride in ether, to the corresponding 5,6,13,13a tetrahydro-8H-isoquino[1,2-b] quinazoline, which is then converted to its quaternary ammonium salt by treatment with a lower linear alkyl halide, e.g. CH I, and the salt reduced with sodium in liquid ammonia to form the corresponding dibenzo [b,h] [1,5]diazecine.

This invention relates to the compounds of the formula:

wherein R R R R B and B and ring A are as defined below, intermediates, pharmaceutic-ally acceptable acid addition salts and quaternary ammonium salts thereof.

Intermediates of Compounds I include compounds of the formulae:

wherein R R R A A and ring A are as defined below;

I III "ice wherein R R R Ring A, A and A are as defined below, and

R rr-Kor A2 it W wherein Ring A is a member selected from the group consisting of ortho-phenylene and ortho-cyclohexylene;

R is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, e.g. methyl, ethyl, propyl and butyl, linear alkoxy having from 1 to 4 carbon atoms, e.g. methoxy, ethoxy, propoxy and butoxy and, taken together with R methylenedioxy (-OCH --O-);

R is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with R1, methylenedioxy;

R is a member selected from the group consisting of a hydrogen atom and methyl;

R is a linear alkyl having from 1 to 4 carbon atoms;

A1 is a member selected from the group consisting of a hydrogen atom, fluoro, chloro, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with A methylenedioxy;

A is a member selected from the group consisting of a hydrogen atom, fluoro, chloro, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with A methylenedioxy;

B1 is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with B methylenedioxy;

B is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with B methylenedioxy; and

X is a member selected from the group consisting of chloro, bromo and iodo, provided that each of A A B and B is a hydrogen atom where Ring A is orthocyclohexylene.

Compounds I include the classes of Compounds Ia; lb; 10 and Id:

3 4 Compounds III include classes of Compounds IIIa; IIIb; IIIc and IIId:

( JH I A2 H Id A IIIa wherein R R R B and B are as defined above. R1

Compounds II include classes of Compounds 11a; 11b; [1c and Hd:

W 26 R O A H N T l 1110 R N 1 H11 35 I 1 H-N q R" N T H CH3N H IlIc 1 II!) N N R1 CH3N W R N H HI T H IIId wherein R R A and A are as defined above.

H Compounds IV include classes of Compounds IVa;

IVb;IVc and IVd: 4 BL I I I RlXe CH3N\ R 69 70 l i IId 1 IVa vherein R R A and A are as defined above.

wherein R R R A A and X are as defined above.

Compounds I may be obtained by the following reaction scheme (R R R R A A X and Ring A being as defined above):

R \2 Re V VI la R q Y N b R 11 K A 9 II r (B /R X o R N R N 1& 31

III IV According to the reaction scheme, step a is a condensation of a dihydroisoquinoline (V) with an isatoic anhydride (VI), e.g. by admixing and heating compounds V and VI, to form a compound II (a isoquino [1,2-b] quinazolin-S-one) Step b is a reduction of the Compound II to the corresponding compound III, e.g. by heating with lithium aluminum hydride (LAH) in a suitable solvent, e.g. diethyl ether (ether).

Step 0 is a conversion of the compound HI to a compound IV, i.e. its corresponding quaternary ammonium salt, by treatment with R X, i.e. a lower alkyl halide, e.g. CH 'I in ether.

In step d the compound IV is reduced with sodium in liquid ammonia to the corresponding compound I. It is noted that where A or A of the compound IV is a hydrogen atom, alkyl, alkoxy or a methylenedioxy then upon reduction, the B and B substituents of the resulting compound I, correspond to A and A of compound IV. However, if any of A and A of compound IV is halo, i.e. fluoro or chloro, then such halo is converted to a hydrogen in step d. Hence, where any of A and A is halo, then the corresponding B or B of the resulting compound I, will be a hydrogen. It is preferred to use compounds IV wherein A and A correspond to the desired B and B substituents of the compound I.

Since step a of the reaction scheme is an idealized illustration, it shows the preparation of compounds II. However, it has been found that in carrying out step a that where R is a hydrogen atom, compounds VII, are also formed, i.e. compounds of the formula VII 1 of the formula:

R q R I VIII I 7 wherein R R A A and Ring A are as defined above.

Compounds 11a, 11b, 11c and 11d may be prepared according to the reaction scheme by using as compound VI an isotoic anhydride, an N-methyl isotoic anhydride, hexahydroisotoic anhydride and N-methyl hexahydroisotoic anhydride, respectively.

Compounds 11a and 1111 can be converted to compounds Ho and 11d, respectively, by hydrogenation by Well-known methods. Where any of A or A of compounds IIa or III) is halo then such halo is converted to a hydrogen atom during the hydrogenation. Example 9, presented hereinafter, illustrates such a conversion.

Compounds I, II, III, VII and VIII are active upon the central nervous system. Compounds I are useful as central nervous system stimulants and also hypotensive agents. They may be administered to mammals either orally or parenterally in daily doses of from 1 to 10 mg./l g. of body weight, e.g., from 50 to 600 mg. per diem, preferably administered in divided doses from 2 to 4 times a day.

Compounds 11, III, VII and VIII are useful as central nervous system depressants, anti-inflammatories and antipyretics. They are administered to mammals either orally or parenterally in daily doses of from 5 to 30 mg./ kg. of body Weight, e.g., from 300 to 1800 milligrams per diem, preferably administered in divided doses 2 to 4 times a day.

Pharmaceutically acceptable acid addition and quaternary ammonium salts of compounds I, III and VIII are equally as effective as compounds I, III and VIII respectively and may be used in a similar manner. The acid addition and quaternary ammonium salts may be prepared according to well-known procedures from compounds I, III and VIII, respectively. They are all useful, in accord with recognized procedures, for the preparation of corresponding pharmaceutically acceptable salts.

Among the pharmaceutically acceptable acid addition salts are salts of organic acids, e.g. tartaric acid; inorganic acids, e.g. hydrochloric acid, hydrobromic acid and sulfuric acid; monobasic acids, e.g. an alkylsulfonic acid, such as methylsulfonic acid (H CSO H); dibasic acids, e.g. succinic acid; tribasic acids, e.g. phosphoric acid and citric acid; saturated acids, e.g. acetic acid; ethylenically unsaturated acids, e.g. maleic acid and fumaric acid; and aromatic acids, e.g. salicylic acid and arylsulfonic acids, such as phenylsulfonic acid. The only limitation on the acid is that the resulting salt be pharmaceutically acceptable; it is preferred, however, that the acid addition salt be water-soluble.

Each of the pharmaceutically active compounds of this invention may be, e.g. incorporated, for oral administration, in a tablet as the sole active ingredient. A typical tablet is constituted by from 1 to 3 percent binder, e.g. :ragacanth; from 3 to percent disintegrating agent, e.g. corn starch; from 2 to 10 percent lubricant, e.g. talzum; from 0.25 to 1.0 percent lubricant, e.g. magnesium itearate; an average dosage of active ingredient; and 1.s. 100 percent of filler, e.g. lactose; all percentages beng by weight. Tablets are prepared according to standrrd tabletting techniques, which are well known in the 1112, employing the necessary amounts of conventional granulating liquids, e.g. alcohol SD30 and purified water. An exemplary tabletting formulation for the instant ac- :ive compounds is:

Alcohol SD-30 urified water Examples illustrative of this invention follow. In the :xample all temperatures are in degrees oentigrade and all percents and parts are by Weight, unless specified otherwise. Parts by weight are related to parts by volume as a kilogram is related to a liter.

EXAMPLE 1 2,3-dimethoxy-5,6, l 3,13a-tetrahydro-8H-isoquino[1,2-b]quinazolin-8-one ail 1 This example illustrates the preparation of :1 Compound II according to step a of the reaction scheme presented above. The title compound is useful as a starting material for preparing Compounds III, IV and I as is illustrated in Examples 2, 3 and 4, respectively.

Heat under reflux a mixture of 6 parts of 6,7-dimethoxy-3,4-dihydroisoquinoline and 5.1 parts of isatoic anhydride in 60 partsby volume of toluene under nitrogen for 16 hours. Cool the mixture, collect the resultant crystalline precipitate and recrystallize from methanol to obtain the title compound, M.P. 164 to 168 C.

Replacing the 6,7-dimethoxy 3,4 dihydroisoquinoline with 6,7-methylenedioxy-3,4-dihydroisoquinoline results, in a similar manner, of the corresponding Compound II.

EXAMPLE 2 This example illustrates the preparation of a Compound III which is useful in preparing Compounds IV, as is illustrated in Example 3.

Add 45 parts of 2,3-dimethoxy-5,6,13,ISa-tetrahydro- 8H-isoquino[1,2-b]quinazolin-8-one suspended in 1500 parts by volume of tetrahydrofuran (THF) to a solution of 14 parts of lithium aluminum hydride (LAH) in 1300 parts by volume of ether and heat under reflux for 40 hours. Cool the reaction mixture, wash with parts by volume of water and filter. Evaporate the filtrate under vacuum to obtain a residue Which is then crystallized from ether to obtain the title compounds, M.P. 170 to 172.

Replacing the 2,3 dimethoxy 5,6,13,13a tetrahydro- 8I-I-isoquino[1,2-b]quinazolin 8 one width 5,6,8a,9,10, 11,12,12a,l3,13a decahydroisoquino[1,2-b]quinaZolin-8- one results in the preparation, in a similar manner, of the corresponding Compound III.

9 EXAMPLE 3 2,3-dimethoxy-5,6,13,13a-tetrahydro-8H-isoquino 1,2-b1quinazoline methiodide 6 CHaI ,1 i

This example illustrates the preparation of the title compound which is a Compound IV which is useful for preparing 2. Compound I as is illustrated in Example 4.

Prepare a solution of 1 part 2,3-dimethoxy-5,6,13,l3atetrahydro-8H-isoquino[1,2-b1quinazoline in 7 parts by volume of CH Cl 3 parts by volume of ether and 3 parts by volume of methyl iodide and allow the solution to stand at room temperature (20 C.) for /2 hour. Evaporate the solution to dryness under vacuum and recrystallize the residue from ethanol to obtain the title compound, M.P. 245 to 250 C.

Replacing the methyl iodide with ethyl bromide results in the preparation, in a similar manner, of the corresponding compound IV.

EXAMPLE 4 8,9-dimethoxy-13-methyl-5,6,11,12,13,14-hexahydrodibenzo [b,h] [1,51diazecine This example illustrates the preparation of a compound I.

Add one part of sodium to a stirred suspension of 4 parts of 2,3-dimethoxy-5,6,l3,13a-tetrahydro-8H-isoquino- [1,2-b1quinazoline methiodide in 100 parts by volume of liquid ammonia cooled in a solid carbon dioxide-acetone bath. Stir for one hour then allow the mixture to evaporate for 16 hours. Add water to the residue and extract with chloroform. Dry the chloroform extracts over sodium sulfate and evaporate under vacuum. Crystallize the residue from ether to obtain the title compound, M.P. 127 to 128 C.

Replacing the 2,3-dimethoxy-5,6,13,13a-tetrahydro-8I-I- isoquino[l,2-b]quinazoline methiodide with 2,3-dibutyl- 5,6,13,13a tetrahydro 8H isoquino[1,2 b] quinazoline methiodide results in the preparation, in a similar manner, of the corresponding compound I.

EXAMPLE -chloro-2,3-dimethoxy-l3-methyl-5,6,13,13a-tetrahydro8H-isoquino 1 ,2-b] quinolin-8-one This example illustrates the preparation of a compound II, which is useful in preparing a compound III, as is illustrated in Example 6. 1

10-chloro-2,3-dimethoxy-13-methyl-5 ,6,13,13a-tetrahydro-SH-isoquino 1,2-b] quinazoline oH3o q CHaO N CHg-N Add 30 parts of 10-chloro-2,3-dimethoxy-1S-methyl- 5,6,13,13a tetrahydro 8H isoquino[1,2 b]quinazolin-8-one in 1500 parts by volume of ether to a refluxing solution of 9 parts of LAH in 1500 parts by volume of ether. Reflux the mixture for 18 hours. Cool the mixture and add 70 parts by volume of water. Filter the mixture and evaporate the filtrate under vacuum. Crystallize the residue from ether to obtain the title compound, M.P.

138 to 140 C.

Replacing the 10 chloro 2,3 dimethoxy l3 methyl 5,6,13,13a tetrahydro 8H isoquino[l,2 b]quinazolin-8-one with 10,11-difluoro-2,3-dimethyl-l3-methyl- 5,6,13,13a tetrahydro 8H isoquino[1,2 b]quinazolin-8-one results in the preparation, in a similar manner, of the corresponding compound III.

EXAMPLE 7 10-chloro-13-methyl-5,6,13,13a-tetrahydro-8H- isoquino[1,2-b]quinazolin-8-one This example also illustrates the preparation of a compound II.

Reflux 29.5 parts of 3,4-dihydroisoquinoline and 32 parts of 6-chloro-N-methyl isotoic anhydride in 250 parts by volume of toluene for 18 hours. Treat the mixture with carbon black and filter. Evaporate the filtrate under vacuum and crystallize the resultant residue from ether to obtain the title compound, M.P. to 132 C.

Replacing the 6-chloro-N-methyl-isotoic anhydride with 5-butoxy-6-methyl-N-methyl isotoic anhydride results in the preparation, in a similar manner, of the corresponding compound II.

1 1 EXAMPLE 8 5,6,13,13a-tetrahydro-8H-isoquino[1,2-b]quinolin-8-one EXAMPLE 9 2,3-dimethyl-13-methyl-5,6,8a,9,10,11,12,12a,13,13adecahydro-8H-isoquino[1,2-b1quinazolin-8-one CH3O- q orno N CHa-N This example illustrates the preparation of a compound [Id from a compound IIb.

Shake a solution of 18 parts of 10-chloro-2,3-dimethoxy 13 methyl 5,6,13,13a-tetrahydro-SH-isoquino [1,2-b]quinazolin-8-one in 150 parts by volume of glacial acetic acid containing 0.5 part of PtO in an atmosphere of hydrogen (at 50 p.s.i.) for 20 hours. Filter the reaction ."nixture through Celite (diatomaceous earth) and evaporate the filtrate under vacuum. Mix the residue with iodium carbonate solution and methylene chloride, re- :over the methylene chloride layer and dry over sodium iulfate, then evaporate to obtain a residue. Crystallize the :"esidue from ether to obtain the title compound, M.P. 146 10 148 C.

Replacing the 10 chloro 2,3 dimethoxy-13-methyl- 5,6,13,13a tetrahydro 8H isoquin0[l,2-b]quinazolinl one with 2 propoxy 13-methy1-5,6,13,13a-tetralydro 8H isoquino[1,2-a]quinazolin-8-one results in he preparation, in a similar manner, of the correspondng compound IId.

EXAMPLE 10 lO-chloro-Z, 3-dimethoxy-5,6-dihydro-8H-isoquino [1,2-b] quinazolin-8-one CHzO This example illustrates the preparation of a compound VII.

Heat under reflux for 16 hours a mixture of 19 parts of 6,7-dimethoxy-3,4-dihydroisoquinoline and 17.5 parts of a 6-chloro isotoic anhydride in 200 parts by volume of toluene. Treat the reaction mixture with carbon black and filter. Evaporate the filtrate under vacuum to a thick paste and triturate with 20 parts by volume of methanol and parts by volume ether and filter to obtain" the title compound, M.P. 255 to 257 C.

Replacing the 6,7-climethoxy 3,4-dihydroisoquinoline with 6,7 dimethyl 3,4 dihydroisoquinoline results in the preparation, in a similar manner, of the corresponding compound VII.

EXAMPLE 1 1 2,3-dimethoxy-5,6-dihydro-8H-isoquino [1,2-b1quinazoline CHaO CHsO l l This example illustrates the preparation of a compound VIII.

Shake a solution of 1 part of 2,3-dimethoxy-5,6,13, 13a tetrahydro 8H isoquino[1,2-b] quinazoline in 100 parts by volume of ethanol, containing 0.2 part of PtO in an atmosphere of hydrogen (50 p.s.i.) for 3 hours. Filter the reaction mixture through Celite and evaporate the filtrate under vacuum. Crystallize the residue twice from methanol to obtain the title compound, M.P. 156 to 159 C.

Replacing the 2,3 dimethoxy 5,6,13,13a tetrahydro- 8H isoquino [1,2 b]quinazoline with 2 propoxy-5,6, 13,13a tetrahydro 8H-isoquino[1,2-b]quinazoline results in the preparation, in a similar manner, of the corresponding compound VIII.

What is claimed is:

1. A member selected from the group consisting of the free base, a pharmaceutically acceptable acid addition salt thereof and a pharmaceutically acceptable quaternary ammonium salt thereof; the free base being of the formula:

wherein:

Ring A is a member selected from the group consisting of ortho-phenylene and orthocyclohexylene;

R is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with R methylenedioxy (O--CH O-);

R is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 carbon atoms, linear alkoxy having from 1 to 4 carbon atoms and, taken together with R methylenedioxy;

R is a member selected from the group consisting of a hydrogen atom and methyl;

R is a linear alkyl having from 1 to 4 carbon atoms;

B is a member selected from the group consisting of a hydrogen atom, linear alkyl having from 1 to 4 car- 13 14 bon atoms, linear alkoxy having from 1 to 4 carbon methoxy-13-methyl-5,6,l1,12,13,14 hexahydro dibenzoatoms, and taken together with B methylenedioxy; [b,h][1,5]diazecine.

and B is a member selected from the group consisting References Cited of a hydrogen atom, linear alkyl having from 1 to 5 UNITED STATES PATENTS 4 carbon atoms, linear alkoxy having from 1 to 4 3,312,689 5/1967 Schmutz et al 260-239 carbon atoms, and taken together with B methylenedioxy; provided that each of B and B is a hydro- NICHOLAS RIZZO Pnmary Exammer gen atom where Ring A is orthocyclohexylene. 10 TIGHE, Assistant Examiner 2. A compound according to claim 1 wherein the free base is of the Formula 1.

3. A compound according to claim 2 which is 8,9-di- 0-25 2 4; 24251, 244, 200, 232 

